In mining operations it is often necessary to handle slurry emanating from flotation or concentrator plants in which ore produced in mines is treated.
One common instance is the use of tailings. slurry from the flotation plant or other kinds of liquid-solids mixture to fill back the excavation chamber or stopes from which ore is extracted. For several decades it has been common practice to re-fill the excavation chamber wherefrom ore is extracted with common rocks, which act to support the roof of the excavation. This is obviously expensive and time consuming. In more recent procedures, the tailing of the plant, which contains unrecoverable residual metals in the fluid, is pumped back into the mine's excavation. In the case of underground operations the tailings usually fill the exploitation chamber and once its liquid content has drained, it solidifies into a substance capable of supporting the roof. This procedure is known as backfilling with tails, and when practiced in shallow or horizontal ore bodies, requires the underground fabrication of frontal walls or dams within the compass of the chamber to force the position of the backfill against the chamber's roof and to separate the backfill from the ore face which is to be cut after the fill is dry. The span of unsupported roof between ore face and backfill is reduced with the frontal dams. Backfilling is often used also to dispose of the tailings in an inconspicuous non-polluting place, often requiring the erection of expensive walls to limit the location of the backfill within the desired bounds.
In another common instance the products of concentrator plants must be transported from the plant's location to the refinery wherein the concentrated products are transformed into metals. It has been common practice for several decades that the slurry products or pulp of the concentration plant are first allowed or forced to dry, and thereafter transported in bulk or in saks. This requires special loading and unloading procedures which are costly. More recently, the pulp from a concentrator plant is pumped as a fluid to a recipient chamber in a transporting vessel, which can be a boat, a tank-truck or a railroad tank car; wherein the fluid material by drainage or other ways is transformed into a solid. For unloading purposes however, once the vessel arrives to its destination, water jets are used to re-transform the solid into pulp which is then pumped to the refinery. This type of loading and unloading in slurry form avoids considerable handling charges, other costs, and time delays.
It is seen that the handling of fluids emanating from concentrator or flotation plants has become in recent times of considerable technical importance with vast economic consequence.